The present invention relates to power tools for cutting vegetation and more particularly to string trimmers.
String trimmers, sometimes referred to as line or nylon trimmers, are often used for cutting and trimming in areas where other cutting tools cannot conveniently reach or perform the cutting job. Vegetation is cut by a string trimmer with a cutting string or line which is caused to rotate at high speed by a rotating head driven by a motor or similar rotary power source.
Electric powered string trimmers usually include a tubular shaft which extends downwardly from a handle to an electric motor. A cutting head is attached to a rotating shaft of the motor, and this head rotates with the shaft. A short length of cutting string extends from the head during operation of the trimmer. One or more handles are provided on the tubular shaft so that the trimmer can be held and operated by the user. Gasoline engine powered trimmers are similar, but the gasoline engine usually is mounted at one end of the tubular shaft and the cutting head at the other, with a long drive shaft connecting the engine and the cutting head.
String trimmers typically have two handles which are attached to and extend from the tubular shaft so that the user can hold and manipulate the trimmer with both hands while trimming vegetation. During operation, string trimmers are subjected to various forces, such as those caused by the rotation of the motor and cutting head, by movement of the trimmer for cutting by the user, and the like. These and other forces in combination with the relatively unbalanced weight distribution of string trimmers make holding and manipulating such trimmers during operation awkward and frequently necessitate that the user hold the trimmer with both hands during operation.